Mills, who was married to Paul McCartney for six years, told The Late Late Show with Ryan Tubridy that she doesn't want to talk about him.
"I don't want this interview to be all about Paul. That umbilical cord was broken," she said."He's married someone else and I agreed to come on the show so it wasn't just all about Paul."
Mills has a lot to talk about as she's a ski-racer with a prosthetic leg, helps animals, owns the biggest vegan company in the world and counsels thousands of people with disabilities.
In spite of the fact that she did not want the interview to be about her ex, she spoke about how she fell out of love with him.
"This is just someone I fell in love with who to me was a normal guy that happened to write a few cool songs in the '60s and a few in '70s," she explained. "Like everyone that's a partner, you fall in love, you get married, you sometimes go ‘Oh my god, this is completely wrong' and you wake up and move on."
She then brought up that it's "boring" to talk about him.
"If I go down the street, all I get is kids coming up to me. Half of them don't even know who he is," she admitted. "That's why he's got to do songs with Rihanna and Kanye West, so people remember [him]."
McCartney, Rihanna and West recently released "FourFiveSeconds,"
a song that came as a surprise when Rihanna dropped the news on Twitter in January. The trio also performed the hit at the 2015 GRAMMYs.